The subject matter of the present disclosure broadly relates to the art of spring devices and, more particularly, to an indicator for determining and/or communicating an estimated remaining life of a spring device or component thereof. Such a system can be included in or otherwise operatively associated with one or more of a gas spring assembly, a control system, a suspension system and/or a method of operation.
The subject matter of the present disclosure may find particular application and use in conjunction with gas spring assemblies of wheeled vehicles, and will be shown and described herein with reference thereto. However, it is to be appreciated that the subject matter of the present disclosure is also amenable to use in other applications and environments, and that the specific uses shown and described herein are merely exemplary. For example, the subject matter of the present disclosure could be used in conjunction with gas spring assemblies of non-wheeled vehicles, support structures, height adjusting systems and actuators associated with one or more of industrial machinery, components thereof and other such equipment. Accordingly, the subject matter of the present disclosure is not intended to be limited to use associated with gas spring assemblies of wheeled vehicles.
Wheeled motor vehicles of most types and kinds include a sprung mass, such as a body or chassis, for example, and an unsprung mass, such as two or more axles or other wheel-engaging members, for example, with a suspension system disposed therebetween. Typically, a suspension system includes a plurality of spring devices, as well as a plurality of damping devices, disposed between the sprung and the unsprung masses that together permit the sprung and unsprung masses of the vehicle to move in a somewhat controlled manner relative to one another. Movement of the sprung and unsprung masses toward one another is normally referred to in the art as jounce motion, while movement of the sprung and unsprung masses away from one another is commonly referred to in the art as rebound motion.
The plurality of spring devices of a suspension system of a vehicle can, in some cases, be of the type and kind referred to as gas spring assemblies that include a flexible sleeve or bellows. In many cases, the flexible sleeve or bellows includes a flexible wall that is formed from an elastomeric material (e.g., natural rubber, synthetic rubber, thermoplastic elastomer). Often, the flexible wall will include one or more layers or plies of elastomeric material with one or more layers or plies of reinforcing material embedded therein. Regardless of the construction, however, the flexible sleeve or bellows at least partially defines a spring chamber that contains pressurized gas (e.g., air) and permits the gas spring assemblies to support a load.
As a result of the relative movement between the sprung and unsprung masses of a vehicle, gas spring assemblies are routinely displaced between extended and compressed conditions, which results in repeated bending and unbending of the flexible sleeve or bellows. Furthermore, known gas suspension systems typically provide the capability of adjusting the height and/or alignment (i.e., leveling) of a sprung mass (e.g., a body or chassis of a vehicle) relative to an unsprung mass thereof (e.g., a wheel-engaging member or axle housing of the vehicle). Such actions can result in additional bending and unbending of the flexible sleeve or bellows of the gas spring assemblies.
Elastomeric devices, such as flexible sleeves and bellows, for example, may, under some conditions, experience a decrease in performance and/or other characteristics as a result of such cyclical flexing (i.e., bending and unbending) as well as physical conditions of use (e.g., gas pressure level, internal spring temperature), exposure to certain environmental conditions and/or agents, or any combination of these and/or other factors. As such, it may be desirable, in some cases, to identify and/or assist in predicting the occurrence of such decreases in performance and/or other characteristics, whether presenting in a somewhat sudden manner over an abbreviated timeframe or in a more gradual manner over an extended duration.
Accordingly, it is believed desirable to develop indicators operative to determine and/or communicate an estimated remaining life of a spring device, as well as gas spring assemblies, control systems and/or suspension systems that include one or more of such indicators. It is also believed desirable to develop methods of determining an estimated remaining life of a spring device or component thereof.